CVE-2023-20175 is an OS command injection vulnerability identified in Cisco Identity Services Engine (ISE) software, a widely deployed network policy management and access control solution. The flaw exists in a specific CLI command where user-supplied input is not properly sanitized, allowing an authenticated local attacker to inject arbitrary OS commands. The attacker must have at least read-only privileges on the device, which is a relatively low privilege level, to exploit this vulnerability. By submitting a crafted CLI command, the attacker can escalate privileges to root, gaining full control over the underlying operating system. This vulnerability affects a broad range of Cisco ISE versions from 2.6.0 up to 3.2.0, including many patch releases. The CVSS v3.1 base score is 8.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and requiring only low privileges and no user interaction. The vulnerability stems from insufficient input validation in the CLI interface, a critical oversight given the privileged nature of CLI commands. While no public exploits have been reported yet, the potential for privilege escalation and full system compromise makes this a significant threat. Cisco has not yet published patches or mitigation details, so organizations must rely on access controls and monitoring to reduce risk. Given Cisco ISE’s role in enforcing network access policies, successful exploitation could allow attackers to manipulate network access controls, disrupt services, or move laterally within networks.

For European organizations, this vulnerability poses a serious risk due to Cisco ISE’s widespread use in enterprise and government networks for identity and access management. Exploitation could lead to full system compromise, allowing attackers to bypass network access controls, manipulate authentication policies, and potentially disrupt critical services. This could impact confidentiality by exposing sensitive network configuration and user data, integrity by altering access policies, and availability by causing service outages or denial of network access. Organizations in sectors such as finance, telecommunications, energy, and public administration, which heavily rely on Cisco ISE for secure network access, are particularly vulnerable. The ability to escalate privileges from low-level read-only access to root could facilitate lateral movement and persistent footholds within networks, increasing the risk of broader compromise. Additionally, the lack of known exploits currently provides a window for proactive mitigation, but also means attackers may develop exploits soon after disclosure. The threat is amplified in environments where privileged CLI access is shared or poorly controlled.

To mitigate this vulnerability, European organizations should immediately review and restrict CLI access to Cisco ISE devices, ensuring only trusted administrators have access and enforcing the principle of least privilege. Implement strong authentication mechanisms and monitor CLI command usage for unusual or unauthorized activity. Network segmentation should be employed to limit access to Cisco ISE management interfaces. Organizations should track Cisco’s security advisories closely and apply patches or updates as soon as they become available. In the interim, consider disabling or restricting the vulnerable CLI commands if feasible. Conduct regular audits of user privileges and remove unnecessary read-only or higher access rights. Employ intrusion detection systems to identify potential exploitation attempts targeting Cisco ISE. Additionally, maintain comprehensive logging and alerting on administrative actions to facilitate rapid incident response. Training administrators on secure CLI usage and awareness of this vulnerability can further reduce risk.